Paper closure member and paper container



May 3, 1955 w. E. AMBERG 2,707,588

PAPER CLOSURE MEMBER AND PAPER CONTAINER Filed July 19, 1951 UnitedStates Patent O PAPER CLSURE MEMBER AND PAPER CONTAINER Walter E.Amberg, Chicago, Ill., assignor to Lily-Tulip Cup Corporation, acorporation of Delaware Application July 19, 1951, Serial No. 237,549

1 Claim. (Cl. 229-43) This invention relates to paper closure membersfor paper containers and the combination thereof.

In my copending application Serial No. 51,043, led September 24, 1948,now Patent No. 2,568,697, granted September 25, 1951, there is disclosedan improved paper closure member for use with a paper container havingan external rim at the open end thereof and an internal groove adjacentthereto. That paper closure member includes a closure wall portion andan integral side flange portion extending upwardly therefrom throughoutthe periphery thereof. The juncture of the closure wall portion and theside flange portion consists of a compressed solid peripheral bead insubstantial planar alignment with the periphery of the closure wallportion and extending beyond the upwardly extending side flange portionto form a reinforced peripheral extension of the closure wall portion.The side ange portion lies adjacent the open end of the paper containerand the compressed solid pe ripheral bead, forming an extension of theclosure wall portion, snaps into the internal groove of the papercontainer and is held rmly therein positively to retain the paperclosure member in the paper container. The side flange portion is alsoprovided with an integral reentrant portion to overlie and receive therim of the paper container to protect the same from dirt andcontamination, to prevent plunging of the closure member into thecontainer and to provide means for snapping the closure member from thecontainer.

That paper closure member of the aforementioned patent applicationeectively seals the paper container against leakage and is firmly heldin place in the paper container, it being snapped into and out of theinternal groove adjacent the open end of the paper container. It isparticularly useful with the larger sized containers such as cups, tubsand the like wherein the containers are relatively heavy and stable.However, it has been found that when such snap acting closure membersare used with smaller sized containers, such as one or two ouncecontainers used as creamers and the like, there is a tendency to spillthe contents of such small sized containers when the closure member issnapped therefrom, the snap acting re moval of the closure membertending to impart a jerk or the like to the small sized container.

The principal objects of this invention are to provide an improved paperclosure member particularly adaptable for use with smaller sized papercontainers and to provide an improved paper container for use therewith,wherein the closure member effectively seals the open end of the papercontainer, wherein the paper closure member is readily applied to thepaper container, wherein the paper closure member is firmly held inplace in the paper container, wherein the paper closure member isreadily removed without tendency to spill the contents of the papercontainer, wherein plunging of the paper closure member into the papercontainer is effectively prevented, and wherein contamination of the rimof the paper container is effectively prevented.

In carrying out these objects of the invention the paper 2,707,588Patented May 3, 1955 fice container, having an open end to be closed bythe paper closure member, is provided with an external rim about itsopen end, an internal shoulder adjacent its open end and a uniforminternal surface between the internal shoulder and the open end. Inaccordance with one form of this invention, the internal dimension ofthe uniform internal surface is greater adjacent the internal shoulderthan at the open end of the paper container to form a uniformly taperedinner surface. ln accordance with another form of this invention theinternal dimension of the uniform internal surface is substantiallyconstant between the shoulder and the open end of the paper container toform a uniform straight inner surface.

The paper closure member for the open end of the aforementioned papercontainer, either form thereof, is a one piece paper closure member andincludes a closure wall portion, and an integral side wall portionextending upwardly and uniformly inwardly from and throughout theperiphery of the closure wall portion with the side flange portion andthe closure wall portion forming an acute angle therebetween. ln otherwords, the side flange portion has a uniform tapered outer surface. Thepaper closure member also has an integral reentrant portion extendingoutwardly from and throughout the periphery of the upper end of the sideflange portion. The external dimension of the closure wall portion isgreater than the internal dimension of the open end of the papercontainer and the external dimension of the upper end of the side flangeportion is substantially the same as the internal dimension of the openend of the paper container.

When the paper closure member is being inserted in the open end of thepaper container, the closure wall portion is flexed to decrease theexternal dimension of the closure wall portion so that it may bereceived through the open end of the paper container. When the paperclosure member is so inserted, the closure wall portion engages theinternal shoulder of the paper container, the side flange portionengages the uniform interior surface of the paper container between theshoulder and the open end thereof, and the reentrant portion receivesthe external rim of the paper container. When the paper closure memberis removed from the paper container by grasping the reentrant portionthereof, the closure wall portion is also flexed to permit removalthereof.

In the first form of paper container of this invention, wherein theinternal dimension of the uniform tapered internal surface is greateradjacent the internal shoulder than at the open end of the papercontainer, those internal dimensions are substantially the same as theexternal dimensions of the closure wall portion and the upper end of theuniform tapered side flange portion, respectively, of the paper closuremember. Here, after the closure Wall portion has been flexed to insertthe paper closure member in the open end of the paper container, itunflexes as it engages the internal shoulder of the paper container toincrease the outer dimension of the closure Wall portion andcorrespondingly the side flange portion of the paper closure member. Theuniform tapered side flange portion of the paper closure member firmlyengages the uniform tapered inner surface of the paper container as theclosure wall portion engages the internal shoulder of the papercontainer to form a tight joint therebetween, in the nature of adovetail joint, firmly to hold the paper closure member in the open endof the paper container. When the paper closure member is removed fromthe paper container by grasping the reentrant portion thereof, theclosure wall portion again exes due to the camming action between thetapered inner surface of the paper container and the tapered side flangeportion of the paper closure member to permit ready removal without anytendency to jerk the paper container with consequent spilling of thecontents.

In the second form of the paper container of this invention, wherein theinternal dimension of the uniform straight internal surface issubstantially constant between the internal shoulder and the open end ofthe paper container, that internal dimension is substantially the sameas the external dimension of the upper end of the side fiange portionand less than the outer dimension of the closure wall portion of thepaper closure member. Iere, after the closure wall portion has beeniiexed to insert the paper closure member in the open end of the papercontainer, it remains flexed as it engages the internal shoulder of thepaper container frictionally to engage the side ange portion of thepaper closure member with the uniform straight internal surface of thepaper container, the flexing of the closure wall portion assuring a firmfrictional grip therebetween. In this way the paper closure member isfirmly held in the open end of this paper container. When the paperclosure member is removed from the paper container by grasping thereentrant portion thereof, the closure wall portion remains fiexed alsoto permit ready removal without any tendency to jerk the paper containerwith consequent spilling of the contents.

In both forms of the paper container and in the single form of paperclosure member of this invention the closure wall portion of the paperclosure member engages the internal shoulder of the paper container andthe uniform side flange portion of the paper closure member engages theuniform inner surface of the paper containerto provide a tight sealbetween the paper closure member and the paper container and to maintainfirmly the paper closure member in the open end of the paper container.The closure wall portion of the paper closure member also coacts withthe internal shoulder of the paper container to prevent plunging of thepaper closure member into the contents within the paper container. Thereentrant portion of the paper closure member protects the external rimof the paper container from dirt and contamination, assists inpreventing plunging of the paper closure member into the contents withinthe paper .f

container, and forms means for removing the paper closure member fromthe paper container. Excellent results may also be obtained by utilizingsubstantially any degree of taper in the uniform internal surface of thepaper container between the straight uniform internal surface (no taper)and a taper corresponding to the taper of the side flange portion of thepaper closure member. Preferably, the taper of the uniform internalsurface of the paper container should not exceed that of the side flangeportion of the paper closure member.

Further objects of this invention reside in the details I ofconstruction of the paper container and of the paper closure member andin the cooperative relationships between the two.

Other objects and advantages of this invention will become apparent tothose skilled in the art upon refer-- ence to the accompanyingspecification, claims and drawing. in which:

Fig. l is an exploded perspective view of one form of the papercontainer of this invention and a paper closure member of this inventionfor use therewith;

Fig. 2 is a vertical sectional view through the paper container andpaper closure member of Fig. 1 and illustrating the paper closure memberseparate from the paper container;

Fig. 3 is a partial vertical sectional view similar to Fig. 2 butillustrating the paper closure member being inserted in the open end ofthe paper container;

Fig. 4 is a partial sectional view similar to Figs. 2 and 3 butillustrating the paper closure member received in the open end of thepaper container; and

Figs. 5, 6 and 7 are partial sectional views similar to Figs. 2, 3 and4, respectively, but illustrating a second form of the paper containerof this invention.

Referring first to Figs. 1 to 4 of the drawing, one form of the papercontainer of this invention is generally designated at 10 and the paperclosure member operating to seal the open end of the paper container isgenerally designated at 11.

The paper container 10 may be any desired construction and have anydesired shape, but for purposes of illustration herein it is shown to belike the paper container of copending application Serial No. 236,571,filed July 13, 1951 by Walter E. Amberg and Stephen W. Amberg. Here thepaper container 10 is formed from a single piece of paper and includes asmooth side Wall 12 which may be tapered for nesting purposes and apleated transverse bottom wall 13 having a central solid paper button 14at r least partially received in a central recess 15. The juncture ofthe pleated bottom wall 13 with the smooth side wall 12 may be providedwith an annular rib 16 for supporting the paper container in an uprightposition.

The paper container 10 has an upper open end 18 and an external rim 19is provided about the open end I8. An internal shoulder 2f) is formed inthe side wall 12 ci the paper container adjacent the open end 18thereof. A uniform internal surface 21 is provided between the internalshoulder 20 and the open end i8 of the paper container 1f). In the formof the invention illustrated in Figs. l to 4 this uniform internalsurface 21 is tapered inwardly from the shoulder, the internal dimensionof the tapered uniform internal surface 21 being greater adjacent theinternal shoulder 20 than at the open end 13 of the paper container.

The paper closure member 11 is a one piece paper closure member and itincludes a closure wall portion 23 and an integral side wall portion 24extending upwardly and uniformly inwardly from and throughout theperiphery of the closure wall portion 23 with the side flange portion 24and the closure wall portion 23 forming an acute angle therebetween. Inother words, the side flange portion 24 has a uniform tapered outersurface. The paper closure member 10 also has an integral reentrantportion 25 extending outwardly from and throughout the periphery of theupper end of the side liange portion 24. The external dimension of theclosure Wall portion 23 is greater than the internal dimension of theopen end 18 of the paper container 10 and the external dimension of theupper end of the side flange portion 24 is substantially the same as theinternal dimension of the open end 18 of the paper container. In otherwords, the taper of the side flange portion 24 and the externaldimensions thereof are substantially the same as the taper of theuniformly tapered inner surface 21 and the internal dimensions thereofof the paper container 10.

When the paper closure member 11 is being inserted in the open end 18 ofthe paper container 10 the closure wall portion 23 is flexed, asillustrated in Fig. 3, to decrease the external dimension thereof sothat it may be received through the open end 18 of the paper container.After the closure wall portion has been so flexed to insert the paperclosure member in the open end of the paper container, the closure wallportion 23 is brought into engagement with the internal shoulder 20 ofthe paper container and as this is done the closure wall portion T3unflexes, as illustrated in Fig. 4, to increase the outer dimensionthereof and correspondingly the outer dimension of the tapered sideflange portion 24. The uniform tapered side flange portion 24 of thepaper closure member thereby firmly engages the uniform tapered innersurface 21 of the paper container as the closure wall portion 23 engagesthe internal shoulder 20 of the paper container to form a tight jointtherebetween, in the nature of a dovetail joint, firmly to hold thepaper closure member in the open end of the paper container.

To remove the paper closure member 11 from the paper container 10 thereentrant portion 25 of the paper closure member is grasped and pulledupwardly. When this is done the closure wall portion 23 again flexes dueto the camming action between the tapered inner surface 21 of the papercontainer and the tapered side flange portion 24 of the paper closuremember to permit ready removal without any tendency to jerk the papercontainer and, hence, avoids spilling of the contents of the papercontainer.

A second form of paper container is generally designated at 27 in Figs.5, 6 and 7. Here the paper container 27 may be like the paper container10 of Figs. l to 4, with the exception that it is provided with auniform straight internal surface 28 between the shoulder 20 and theopen end 18 of the paper container instead of the uniform taperedinternal surface 21. in other words, the uniform straight internalsurface 28 has an internal dimension which is substantially constantbetween the internal shoulder 20 and the open end 18 of the papercontainer. The same paper closure member 11 is utilized with this formof the paper container. The internal dimension of the uniform straightinternal surface 28 is substantialiy the same as the external dimensionof the upper end of the side flange portion 24 and less than theexternal dimension of the closure wall portion 23 of the paper closuremember 11.

When the paper closure member 11 is inserted into the open end 18 of thepaper container 27, the closure wall portion 23 is liexed, asillustrated in Fig. 6, to permit the insertion. inserted so that theclosure wall portion 23 engages the internal shoulder 20 of the papercontainer' 27, the closure wall portion 23 remains exed as illustratedin Pig. 7. This causes the side ange portion 24 of the paper closuremember 11 frictionally to engage the uniform straight internal surface28 of the paper container, the flexing of the closure Wall portion 23assuring a firm frictional grip therebetween. In this way the paperclosure member 11 is firmly held in the open end of the paper container27. When the paper closure member 11 is removed from the paper container27 by grasping the reentrant portion thereof and pulling upwardlythereon, the closure wall portion 23 remains flexed also to permit readyremoval without any tendency to jerk the paper container with consequentspilling of its contents.

In both forms of the paper containers and 27, and in the single form ofpaper closure member 11, the closure wall portion 23 of the paperclosure member engages the internal shoulder of the paper container andthe uniform side flange portion 24 of the paper closure member engagesthe uniform inner surface 21 or 28 of the paper containers to provide atight seal between the paper closure member 11 and the paper containers10 and 27 and to maintain firmly the paper closure member 11 in the openend 18 of the paper containers. The closure wall portion 23 of the paperclosure member 11 also coacts with the internal shoulder 20 of the papercontainers to prevent plunging of the paper closure member into thecontents Within the paper containers. The

reentrant portion 25 of the paper closure member 11 protetcs theexternal rim 19 of the paper containers from dirt and contamination,assists in preventing plunging of the paper closure into the contentswithin the paper containers and forms means for removing the paperclosure member from the paper containers.

While the paper container 10 is shown to have an internal taperedsurface 21, corresponding in degree and dimension to the tapered sideflange portion 24 of the paper closure member 11, and while the papercontainer 27 is shown to have a substantially straight uniform internalsurface 28, excellent results may also be obtained by utilizingsubstantially any degree of taper in the uniform internal surface of thepaper container, which may vary between the straight uniform internalsurface 28 of Figs. 5 to 7 and a taper corresponding to the taper of theside flange portion 24 of the paper closure member 11.

When the paper closure member 11 is fully Preferably, the taper of theuniform internal surface of the paper container should not exceed thatof the side flange portion of the paper closure member. The uniforminternal surfaces between the internal shoulder and the open end of thepaper container are angularly inverted from the body of the container.The external dimensions of the paper closure member 11 and thecooperating internal dimensions of the paper containers 10 and 27 are soselected as to maintain a tight fit between the paper closure membersand the paper containers. However, due to the particular constructionsof the paper closure members and paper containers, close tolerances inmanufacture of the same are not necessary. The principles of thisinvention may also apply to containers and closure members made ofmaterials other than paper, such as other resilient materials includingplastics and the like.

While for purposes of illustration several forms of this invention havebeen disclosed, other forms thereof may become apparent to those skilledin the art upon reference to this disclosure and, therefore, thisinvention is to be limited only by the scope of the appended claim.

I claim as my invention:

In combination, a paper container having an open end, an external rimabout its open end, an internal shoulder adjacent its open end and auniform internal surface between the internal shoulder and the open end,and a one piece resilient paper closure member for the open end of thecontainer including a closure wall portion, an integral side flangeportion extending upwardly and uniformly inwardly from and throughoutthe periphery of the closure Wall portion with the side flange portionand the closure wall portion forming an acute angle therebetween and anintegral external reentrant portion extending outwardly from andthroughout the periphery of the upper end of the side flange portion,the external dimension of the closure wall portion being greater thanthe internal dimension of the open end of the container and at leastsubstantially as great as the internal dimension of said internalsurface adjacent the internal shoulder and the external dimension of theupper end of the side flange portion being substantially the same as theinternal dimension of the open end of the container, the closure wallportion being flexed as the closure member is inserted in the open endof the container and, when inserted, the closure Wall portion engagingthe internal shoulder of the container, the side flange portionfrictionally engaging substantially the entire interior of the containerbetween the shoulder and the open end thereof, and the reentrant portionreceiving the external rim of the container.

References Cited in the file of this patent UNITED STATES PATENTS631,852 Kinnard Aug. 29, 1899 1,064,787 Taylor June 17, 1913 1,190,723Caylor July 11, 1916 1,224,778 Palm May 1, 1917 1,343,724 Hulbert .lune15, 1920 1,469,067 Coates Sept. 25, 1923 1,627,048 Moore May 3, 19272,154,214 Roach et al Apr. 11, 1939 2,377,599 Allen June 5, 19452,396,035 Billings et al. Mar. 5, 1946 2,420,738 Dickerman May 20, 19472,455,063 Jackson Nov. 30, 1948 2,568,697 Amberg Sept. 25, 1951 FOREIGNPATENTS 924,467 France Mar. 10, 1947 613,278 Great Britain Nov. 24, 1948

